Hey all,
I have a Holset on my 1.9 and can seldom get over 10-12 psi - I even have the wastegate wired shut
. I have seen 18 but not for some time now. It seems fairly obvious to me that I must have some boost leaks. I did a leak test many months ago, found one and fixed it. I still cant get my boost where I want it to reach which is 20 psi.
During the leak-down test, I could hear air going into the motor and figured it was because I didn't have the engine at TDC. Why I didn't just crank it a bit to close the valves I don't recall but I must have figured the leak I found was the culprit - apparently I have more leaks or there is some other issue.
To explain how it feels when driving, when I get on a freeway on ramp and floor it, boost climbs quickly to about 10-12, then the engine begins to stumble like it's running out of fuel and boost stops climbing. I back the pedal off a tad and it smooths back out - add pedal, stumble - like I hit a wall.
I have messed with the LDA, changed springs, and adjusted the LDA spring seat plate and while it did seem to help some, the problem still exists. I can get a bit of smoke if I really tromp on it and I'd rather not turn the fuel screw any more as my mileage is already not that great.
Other than this one issue, the engine runs like a champ - thanks to a lot of help I have received here. I'm going to do another leak-down test this morning and would like to know if having the valves closed (TDC) is required. Also, if anyone has any other reasons that could cause this stumble/low boost issue, please let me know.
Thanks,
Jim